Bar code label identification circuit

Abstract

A method for forming UPC or EAN bar code labels from scans of half labels or less than half labels requires that captured data be examined and classified as being either a first type of data configuration or a second type. A first type includes a given number of numeric characters delimited by both margin and center characters. A second type includes either a margin character or a center character and a given number of numeric characters. Labels are formed, where possible, by using appropriate first type data configurations. If labels cannot be formed using only first type configurations, second type configurations are examined to determine if they could represent different portions of the same region (left or right) of a label. If complementary second type configurations are found, they are merged to form a half label. The formed half label may be further merged with a complementary first type data configuration to form a complete label.

Having thus described my invention with reference to a preferred embodiment thereof, what I desire to secure by Letters Patent is: 
     
       1. For use in reading a label of a type including a plurality of numeric characters bounded by standard delimiter characters, including a margin character and a center character, a method of forming a label using data captured by multiple scans of the label where no scan includes both delimiter characters, said method including the steps of: determining whether captured data includes a first data configuration having at least one delimiter character and (n/2)+1 numeric characters where n is the number of numeric characters bounded by the delimiter characters;   determining whether captured data also includes a second data configuration having the other delimiter character and (n/2)+1 numeric characters;   determining whether the numeric characters in the first and second data configurations satisfy predetermined parity requirements;   comparing the numeric values of characters occupying common positions in the two data configurations; and   forming a label from the two data configurations only when the numeric characters occupying overlapping positions in the two configurations have the same numeric values and the numeric characters have been found to satisfy the predetermined parity requirements.   
     
     
       2. A method as defined in claim 1 including the additional steps of: determining whether captured data also contains a third data configuration including another set of numeric characters bounded by both delimiter characters;   determining whether the numeric characters in the third data configuration satisfy predetermined parity requirements;and   combining the label formed by the merger of the first two data configurations with the third data configuration to provide a complete label.   
     
     
       3. For use in reading a bar code label of a type which includes at least one set of numeric characters bounded by standard delimiter characters, including a margin character and a center character, a method of forming a label using data captured by multiple scans of the label where certain scans fail to include both types of delimiter characters, said method comprising the steps of: examining captured data to determine whether such data includes a first type of data configuration, such configuration having both kinds of delimiter characters and a set of numeric characters;   examining each data configuration of the first type to determine whether the numeric characters meet predetermined parity requirements;   classifying each first type in which the numeric characters meet the predetermined parity requirements as representing a particular portion of a particular kind of bar code label;   examining captured data to determine whether such data includes at least one second type of data configuration, each such configuration having only one delimiter character and a predetermined minimum number of numeric characters;   examining each data configuration of the second type to determine whether the numeric characters meet predetermined parity requirements;   classifying each second type of data configuration as representing a particular portion of a particular kind of bar code label on the basis of the particular delimiter character and the parity of the numeric characters in each such second type;   determining whether there are two second type data configurations representing adjacent portions of a particular kind of label;   comparing the numeric values of characters occupying common positions in each such pair of second type data configurations;   merging each such pair of second type data configurations only when the numeric characters occupying overlapping positions have the same numeric values to form a single data configuration having both kinds of delimiter characters and a single set of numeric characters; and   forming a complete label from a given first type of data configuration and a given single data configuration when such configurations have been classified as representing different portions of the same kind of bar code label.   
     
     
       4. A method as defined in claim 3 wherein the different kinds of bar code labels which can be formed include UPC Version A, UPC Version E, EAN-8 and EAN-13 format labels. 
     
     
       5. A method as defined in claim 4 including the steps of: identifying any first type data configurations representing the left and right sides of a UPC Version A label and forming such a label by the merger of such identified configurations;   if a UPC Version A label cannot be formed from first type data configurations, identifying any first type configurations representing the left and right sides of an EAN-13 label and forming such a label by the merger of such identified configurations;   if an EAN-13 label cannot be formed from first type data configurations, identifying any first type data configurations representing the left and right sides of an EAN-8 label;   examining the processed data to determine whether such data includes configurations indicative of any UPC Version A, UPC Version E or EAN-13 label;   forming an EAN-8 label from the identified first type configurations only if the examined data does not indicate the possible existence of another kind of label;   if an EAN-8 label cannot be formed, testing identified first types of data configurations to determine whether any of such types can be used to form a UPC Version E label and forming such a label only if the identified configurations have been found more than once during a scan session;   if a UPC Version E label cannot be formed, identifying any first type of data configuration classified as representing the right side of an EAN-13 or UPC Version A label and any second types of data configurations representing different portions of the left side of either an EAN-13 or UPC Version A label;   determining whether the identified second types represent either an EAN-13 or a UPC Version A label on the basis of the parity pattern of the numeric characters and forming either a complete EAN-13 or a complete UPC Version A label by the merger of the identified first type and the merger of the identified second types;   if neither an EAN-13 nor a UPC Version A label can be formed, examining the data to identify a first type representing the left side of either a UPC Version A label and any second types representing different portions of the right side of a UPC Version A label;   forming a complete UPC Version A label using the identified first type and a merger of the identified second types;   if a UPC Version A label cannot be formed, examining the data to identify any first type representing the left side of an EAN-13 label and any second types representing different portions of the right side of an EAN-13 label;   forming a complete EAN-13 label using the identified first type and a merger of the identified second types; and   discarding all data if a complete label cannot be formed by any of the foregoing steps.